The present invention relates to a dynamic semiconductor memory device having a complementary metal oxide semiconductor sense amplifier (referred to as a CMOS sense amplifier hereinafter), and more particularly to a drive device for the CMOS sense amplifier which can drive the CMOS sense amplifier without causing fluctuations in the ground potential and power supply potential.
FIG. 3 is a block diagram schematically illustrating a CMOS sense amplifier of a conventional dynamic semiconductor memory device and a drive device therefor. As illustrated in FIG. 3, a P-channel MIS (metal insulator semiconductor) FET drive line 41 connected to the CMOS sense amplifier 33 is connected through a switching element 31 to a power supply line 21 having the same electrical potential as the power supply terminal, and a N-channel MIS FET drive line 42 is connected through a switching element 32 to a ground line 22 having the same electrical potential as the ground terminal. The P-channel MIS FET (not shown) in the CMOS sense amplifier 33 is driven by closing the switching element 31 so that continuity exists, and the N-channel MIS FET (not shown) in the CMOS sense amplifier 33 is driven by closing the switching element 32 so that continuity exists.
When the above described conventional dynamic semiconductor memory device has multiple CMOS sense amplifiers 33 and all sense amplifiers 33 are simultaneously driven by their respective drive devices of the above described structure, the following problem is presented. That is, when the CMOS sense amplifiers 33 are simultaneously driven, a comparatively large current with respect to the current capacity of the power supply line 21 and the ground line 22 flows. Then the power supply potential and the ground potential fluctuate, and common mode noise which lowers reliability of the dynamic memory device is generated in the vicinity.